Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:60921
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.217.170 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <CALtuQzCj+FQM6ntADvfDWxqr0SjVzdJUs8KUOnQGqCaXDzXBHw@mail.gmail.com>
References: <CAGovj_M=nq3DzPh_vLL+C+ujAv0o+WqB7iRaj=OFLO2JOb7QgA@mail.gmail.com>
	<CALtuQzCj+FQM6ntADvfDWxqr0SjVzdJUs8KUOnQGqCaXDzXBHw@mail.gmail.com>
Date: Thu, 21 Jun 2012 08:11:30 -0400
Message-ID: <CAGovj_PEmjH3So_3RRMQC3oGVg6gL39JQW17W=5gfXUzHGSshQ@mail.gmail.com>
To: PHP Internals List <internals@lists.php.net>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Subject: Re: [PHP-DEV] Resume keyword
From: dmgx.michael@gmail.com (Michael Morris)

On Thu, Jun 21, 2012 at 2:59 AM, Sebastian Krebs
<krebs.seb@googlemail.com> wrote:
> 2012/6/20 Michael Morris <dmgx.michael@gmail.com>
>
>> [/snip]
>>
>> An example for additional clarity.
>>
>> set_exception_handler(function ($e) {
>> =A0echo $e->getMessage();
>> =A0// Don't know if this is correct - but should be able to illustrate h=
ere
>> =A0if ($e->getCode() =3D=3D E_NOTICE & E_STRICT) {
>> =A0 =A0resume null;
>> =A0}
>>
>> =A0echo 'Dying now'; exit;
>> });
>>
>> throw new Exception('A test', E_NOTICE);
>>
>> echo "We didn't die";
>>
>> The code above when run would echo "A test. We didn't die.";
>>
>>
>>
> Whats about
>
> $user =3D $this->getUser(); // Throws exception
> echo $user->getName();
>
>
> Now the second one will fail too, but in reality it shouldn't even get
> executed...
>
> Regards,
> Sebastian
>
>

Then the error handler shouldn't have called resume.  The error
handler should only call the keyword if its safe to do so.  And now
that I think about it, not having the ability to return anything would
be for the best since it would keep the usefulness of this to a
minimum and avoid magic headaches.

Cause the last thing we need is for people to start using the
exception handling mechanism as additional control structure tree.

What about what I'd mentioned before that this would allow?  With this
in place the existing PHP Errors could all be converted to Exceptions.
 The default exception handler would resume after catching any low
level exceptions (E_NOTICE, E_WARNING, etc) but a custom one can be
free to do whatever.

Unifying the mechanisms also would allow for exceptions for other
fatal events.  This would be highly useful.

try {
  require( 'path/to/file.php' );
} catch ( PARSE_EXCEPTION $e ) {
  // some logging then pretty death
}

Most of the time you'd never want to resume after such an
exception.... Most of the time.

In any event "resume" would allow PHP to get back to having only one
exception mechanism instead of two since the behavior of errors could
be emulated under exceptions. That is the principle boon of resume.

Does that balance the two drawbacks
1) It's a new keyword, so BC breaks occur with code that used it as a
function name.
2) The spaghetti possibilities increase.